For quite a few systems I've built recently, I've used a Raspberry Pi connected to an Arduino Nano over USB. The Nano is the I/O expansion for the Pi. This combination is cheap (£35 total) and really flexible. Having them bundled would be useful sometimes, but equally often it's useful to have the small size of the nano located close to where I want the I/O and the larger Pi can be put elsewhere. So unless these boards are around the same price point, I'll give them a miss.

I suspect these boards are being released in response to the rasberry pi, although I can't say for certain they're an appropriate replacement. Besides its not as if they're ending the old line of arduino boards, so if you don't like the new ones... just don't buy them :)

I'm sure you're right about the new boards being a response to the rpi. I just have mixed feelings about the possibility of competition between two open source hardware systems. Maybe it'll produce innovation, or maybe just duplication of effort.

"if you don't like the new ones... just don't buy them"

I didn't say I disliked them. Since I didn't make myself clear: I do wish them well.

I'd guess that pin compatibility with existing Arduino shields is pretty important. Also, the TRE has both an AVR processor which can run the standard Arduino code as well as an ARM processor for running Linux. So you could use the AVR for low-latency polling of the GPIO pins while using the ARM for communicating over what looks like an ethernet port, four USB ports, two audio jacks, and an HDMI port.

Raspberry Pi doesn't have enough pins for some projects. With a Linux system, neither one of them are suitable for real-time updates.

I'm working on a rover project that uses Raspberry Pi for WiFi and HD video processing, and Arduino for motor control. Best of both worlds. The TRE board sounds perfect if it can come in at a similar price point.